Use of surface modified diamond to manufacture polycrystalline diamond

ABSTRACT

A superabrasive blank and a method of making the superabrasive blank are disclosed. A superabrasive blank may comprise a plurality of polycrystalline superabrasive particles made of surface modified superabrasive particles. The surface modified superabrasive particles may have sphericity less than about 0.70. The substrate attached to a superabrasive volume formed by the polycrystalline superabrasive particles.

TECHNICAL FIELD AND INDUSTRIAL APPLICABILITY

The present invention relates generally to superabrasive materials and a method of making superabrasive materials; and more particularly, to polycrystalline diamond (PCD) by using surface modified diamond.

SUMMARY

In one embodiment, superabrasive blank may comprise a plurality of polycrystalline superabrasive particles made of surface modified superabrasive particles, wherein the surface modified superabrasive particles have sphericity less than about 0.70; and a substrate attached to a superabrasive volume formed by the polycrystalline superabrasive particles.

In another embodiment, a method may comprise steps of providing surface modified superabrasive particles, wherein the surface modified superabrasive particles have surface roughness less than about 0.89; providing a substrate attached to a superabrasive volume formed by the plurality of superabrasive particles; and subjecting the substrate and the superabrasive volume to conditions of elevated temperature and pressure suitable for producing the polycrystalline superabrasive material.

In yet another embodiment, a superabrasive blank may comprise a plurality of polycrystalline superabrasive particles made of surface modified superabrasive particles, wherein the surface modified superabrasive particles have surface roughness less than about 0.89.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing summary, as well as the following detailed description of the embodiments, will be better understood when read in conjunction with the appended drawings. It should be understood that the embodiments depicted are not limited to the precise arrangements and instrumentalities shown.

FIG. 1 is schematic perspective view of a cylindrical shape polycrystalline blank produced in a high pressure high temperature (HPHT) process according to an exemplary embodiment;

FIG. 2 a is a scanning electron microscope (SEM) image of surface modified diamond using a nickel coating process or diamond modified using an iron powder process;

FIG. 2 b is an enlarged scanning electron microscope (SEM) image of surface modified diamond according to FIG. 2 a;

FIG. 3 is a flow chart illustrating a method of manufacturing polycrystalline blank according to an embodiment;

FIG. 4 is illustrating a concept of ferret tangent and ferret diameter according to an embodiment;

FIG. 5 is illustrating a concept of convex perimeter which is formed from the intersection of many Feret tangent lines according to an embodiment;

FIG. 6 is illustrating concepts of perimeter and convex perimeter according to an embodiment;

FIG. 7 a is illustrating microstructure of polycrystalline diamond blank using surface modified diamond feed; and

FIG. 7 b is illustrating microstructure of polycrystalline diamond blank using conventional diamond feed.

DETAILED DESCRIPTION

Before the present methods, systems and materials are described, it is to be understood that this disclosure is not limited to the particular methodologies, systems and materials described, as these may vary. It is also to be understood that the terminology used in the description is for the purpose of describing the particular versions or embodiments only, and is not intended to limit the scope. For example, as used herein, the singular forms “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise. In addition, the word “comprising” as used herein is intended to mean “including but not limited to.” Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art.

Unless otherwise indicated, all numbers expressing quantities of ingredients, properties such as size, weight, reaction conditions and so forth used in the specification and claims are to the understood as being modified in all instances by the term “about”. Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

As used herein, the term “about” means plus or minus 10% of the numerical value of the number with which it is being used. Therefore, about 50 means in the range of 45-55.

As used herein, the term “superabrasive particles” may refer to ultra-hard particles or superabrasive particles having a Knoop hardness of 5000 KHN or greater. The superabrasive particles may include diamond, and cubic boron nitride, for example. The term “abrasive”, as used herein, refers to any material used to wear away softer material.

The term “material removal”, as used herein, refers to the weight of a workpiece removed in a given period of time reported in milligrams, grams, etc.

The term, “material removal rate”, as used herein, refers to material removed divided by the time interval reported as milligrams per minute, grams per hour, etc.

The term “monocrystalline diamond”, as used herein, refers to a diamond that is formed either by high-pressure/high-temperature synthesis or a diamond that is naturally formed. Fracture of monocrystalline diamond proceeds along atomic cleavage planes. A monocrystalline diamond particle breaks relatively easily at the cleavage planes.

The term “particle” or “particles”, as used herein, refers to a discrete body or bodies. A particle is also considered a crystal or a grain.

The term “pit”, as used herein, refers to an indentation or crevice in the particle, either an indentation or crevice in the two-dimensional image or an indentation or crevice in an object.

The term “polycrystalline diamond”, as used herein, refers to diamond formed by explosion synthesis or high pressure high temperature resulting in a polycrystalline particle structure. Each polycrystalline diamond particle consists of large numbers of monocrystalline particles of any sizes. Polycrystalline diamond particles do not have cleavage planes.

The term “spike”, as used herein, refers to a sharp projection pointing outward from the centroid of a particle, a sharp projection pointing outward from the centroid of a two-dimensional image or a sharp projection pointing outward from an object.

The term “superabrasive”, as used herein, refers to an abrasive possessing superior hardness and abrasion resistance. Diamond and cubic boron nitride are examples of superabrasives and have Knoop indentation hardness values of over 3500.

The term “weight loss”, as used herein, refers to the difference in weight of a group of particles before being subject to the modification treatment and the weight of the same mass of diamond particles or abrasive particles after being subjected to the modification treatment.

The term “workpiece”, as used herein, refers to parts or objects from which material is removed by grinding, polishing, lapping or other material removal methods.

The term “perimeter”, as used herein, refers to the boundary of a closed plane figure or the sum of all borders of a two-dimensional image.

The term “convex perimeter”, as used herein, refers to a line joining Feret tangent points, where Feret is the distance between two parallel tangents touching the boundary on each side of a two dimensional image or object. FIGS. 4-6 provide illustrations of these concepts. Feret diameter is defined as the distance between two parallel lines touching the boundary of a 2-dimensional image or particle profile. The convex perimeter is formed from the intersection of many Feret tangent lines.

The term “surface roughness”, as used herein, refers to the measurement of a two-dimensional image that quantifies the extent or degree of pits and spikes of an object's edges or boundaries as stated in the CLEMEX image analyzer, Clemex Vision User's Guide PE 3.5 ©2001. Surface roughness is determined by the ratio of the convex perimeter divided by the perimeter.

${{Surface}\mspace{14mu} {Roughness}} = \frac{ConvexPerimeter}{Perimeter}$

Note that as the degree of pits and spikes increases, the surface roughness factor decreases.

The term “sphericity”, as used herein, refers to the estimate of the enclosed area of a two dimensional image or object (4πA) divided by the square of perimeter (p²).

${Sphericity} = \frac{4\pi \; A}{p^{2}}$

The term “surface area” as used herein, refers to the external surface of a particle. When used with a plurality of particles, i.e., powder, the term specific surface area is used and is reported as surface area per gram of powder.

The terms diamond particle or particles and diamond powder or powders are used synonymously in the instant application and have the same meaning as “particle” defined above.

It is important to note that although the terms defined above refer to measuring two-dimensional particle profiles using microscopic measuring techniques, it is understood that the features extend to the three-dimensional form. Automated image analysis of particle size and shape is recognized by one skilled in the art as a reliable, reproducible method of measuring particle characteristics. Although the CLEMEX image analyzer was used, similar devices are available that may reproduce the data.

In one embodiment, monocrystalline diamond particles may be used. Monocrystalline diamond particles in sizes of less than about 100 microns are useful. However, diamond particles in sizes over about 100 microns may be used as well. The sizes of the diamond particles range from about 0.1 to about 1000 microns. One example of diamond particles that may be used is SJK-5 4-8 micron, synthetic industrial diamond particles manufactured by Diamond Innovations, Inc. (Worthington, Ohio, U.S.A).

In another embodiment, natural diamond particles, sintered polycrystalline diamond or shock synthesized polycrystalline diamond particles may be subjected to the modification treatment discussed below.

In an embodiment, other abrasives may be subjected to a modification treatment. Examples of abrasives include any material, such as minerals, that are used for shaping or finishing a workpiece. Superabrasive materials such as natural and synthetic diamond and boron, carbon and nitrogen compounds may be used. Suitable diamond materials may be crystalline or polycrystalline. Other examples of abrasive grains may include calcium carbonate, emery, novaculite, pumice dust, rouge, sand, ceramics, alumina, glass, silica, silicon carbide, and zirconia alumina.

In another embodiment, a reactive coating is used to modify the abrasive or superabrasive particles. Such reactive coatings include but are not limited to alkali metal hydroxides, such as lithium hydroxide, sodium hydroxide, potassium hydroxide, potassium carbonate, sodium peroxide, potassium dichromate and potassium nitrate, etc. The reactive coatings may also include a combination of alkali metal hydroxides.

Still other examples of metals that may be utilized as the reactive coating are those included in Group VIII of the Periodic table, their metal compounds and combinations thereof. Other examples of material that may be used as reactive coatings include the catalyst metals taught in U.S. Pat. No. 2,947,609 and the catalyst metals taught in U.S. Pat. No. 2,947,610.

Polycrystalline diamond composite (or “PCD”, as used hereafter) may represent a volume of crystalline diamond grains with embedded foreign material filling the inter-grain space. In one particular case, composite comprises crystalline diamond grains, bound to each other by strong diamond-to-diamond bonds and forming a rigid polycrystalline diamond body, and the inter-grain regions, disposed between the bound grains and filled with a catalyst material (e.g. cobalt or its alloys), which was used to promote diamond bonding during fabrication. Suitable metal solvent catalysts may include the metal in Group VIII of the Periodic table. In another particular case, polycrystalline diamond composite comprises a plurality of crystalline diamond grains, which are not bound to each other, but instead are bound together by foreign bonding materials such as borides, nitrides, carbides, e.g. SiC.

Polycrystalline diamond blanks and PCD cutters may be fabricated in different ways and the following examples do not limit a variety of different types of diamond composites and PCD cutters which may be coated according to an embodiment. In one example, polycrystalline blank are formed by placing a mixture of diamond polycrystalline powder with a suitable solvent catalyst material (e.g. cobalt) on the top of WC—Co substrate, which assembly is subjected to processing conditions of extremely high pressure and high temperature (HPHT), where the solvent catalyst promotes desired inter-crystalline diamond-to-diamond bonding and, also, provides a binding between polycrystalline diamond body and substrate support. In another example, polycrystalline blank is formed by placing diamond powder without a catalyst material on the top of substrate containing a catalyst material (e.g. WC—Co substrate). In this example, necessary cobalt catalyst material is supplied from the substrate and melted cobalt is swept through the diamond powder during the HPHT process. In still another example, a hard polycrystalline diamond composite is fabricated by forming a mixture of diamond powder with silicon powder and mixture is subjected to HPHT process, thus forming a dense polycrystalline cutter where diamond particles are bound together by newly formed SiC material.

Abrasion resistance of polycrystalline diamond composites and PCD cutters may be determined mainly by the strength of bonding between diamond particles (e.g. cobalt catalyst), or, in the case when diamond-to-diamond bonding is absent, by foreign material working as a binder (e.g. SiC binder), or in still another case, by both diamond-to-diamond bonding and foreign binder.

The presence of some catalysts inside the polycrystalline diamond body promotes the degradation of the cutting edge of the cutter during the cutting process, especially if the edge temperature reaches a high enough critical value. Probably, the cobalt driven degradation may be caused by the large difference in thermal expansion between diamond and catalyst (e.g. cobalt metal), and also by catalytic effect of cobalt on diamond graphitization. Removal of catalyst from the polycrystalline diamond body of PCD cutter, for example, by chemical etching in acids, leaves an interconnected network of pores and a residual catalyst (up to 10 vol %) trapped inside the polycrystalline diamond body. It has been demonstrated that a chemically etched polycrystalline diamond cutter by removal of a substantial amount of cobalt from the PCD cutter significantly improves its abrasion resistance. Also it follows that a thicker cobalt depleted layer near the cutting edge provides better abrasion resistance of the PCD cutter than a thinner cobalt depleted layer.

As shown in FIG. 1, a superabrasive cutter 10 which is insertable within a downhole tool, such as a drill bit (not shown) in according to an embodiment. One example of the superabrasive cutter 10 may include a superabrasive volume 12 having a top surface 21. The superabrasive blank may comprise a plurality of polycrystalline superabrasive particles made of surface modified superabrasive particles shown in FIG. 2 a. The surface modified superabrasive particles have sphericity less than about 0.70.

In one embodiment, the superabrasive blank may be a standalone blank without a substrate. In another embodiment, the superabrasive cutter 10 may include a substrate 20 attached to the superabrasive volume 12 formed by the polycrystalline superabrasive particles. The substrate may be metal carbide, attached to the superabrasive volume 12 via an interface 22 between the superabrasive volume 12 and the metal carbide. The metal carbide may be generally made from cemented cobalt tungsten carbide, or tungsten carbide, while the superabrasive volume 12 may be formed using a polycrystalline ultra-hard material, such as polycrystalline diamond, polycrystalline cubic boron nitride (“PCBN”), or tungsten carbide mixed with diamond crystals (impregnated segments). The superabrasive particles may be selected from a group of cubic boron nitride, diamond, and diamond composite materials.

One embodiment pertains to monocrystalline diamond particles having very rough, irregular surfaces as shown in FIG. 2 a. The particles have been modified using the method described below. In addition to the roughened appearance, the modified diamond particles have unique characteristics as compared to conventional monocrystalline diamond particles.

FIG. 2 b shows an enlargement of a surface modified diamond particle from FIG. 2 a. The surface modified diamond particles 24 contain one or more pits and/or spikes. An example of a diamond particle exhibiting these features is shown in FIG. 2 b. Diamond particle 1, having a weight loss of about 45%, includes pits 26, 28 that form spike 29. The lengths of the spikes and depths of the pits vary according to the modification treatment parameters. The average depth of the pits on a particle ranges in size from about 5% to about 70% of the longest length of the particle.

As shown in FIG. 1 b, the modified diamond particles 24 include significantly more spikes and pits than conventional monocrystalline diamond. The spikes 29 act as cutting edges when used in free-abrasive slurry applications. It has been discovered that the performance of the diamond particles of the instant application significantly improves when used in free abrasive lapping applications within a liquid slurry or suspension. When the modified diamond particles are used in a fixed bond system, the pits and the spikes help secure the particle within the bond system.

The superabrasive cutter 10 may be fabricated according to processes known to persons having ordinary skill in the art. The cutting element 10 may be referred to as a polycrystalline diamond compact (“PCD”) cutter when polycrystalline diamond is used to form the polycrystalline volume 12. PCD cutters are known for their toughness and durability, which allow them to be an effective cutting insert in demanding applications. Although one type of superabrasive cutter 10 has been described, other types of superabrasive cutter 10 may be utilized. For example, in some embodiment, superabrasive cutter 10 may have a chamfer (not shown) around an outer peripheral of the top surface 21. The chamfer may have a vertical height of 0.5 mm and an angle of 45° degrees, for example, which may provide a particularly strong and fracture resistant tool component.

As shown in FIG. 2, a method 30 of making superabrasive material may comprise steps of providing surface modified superabrasive particles, wherein the surface modified superabrasive particles have surface roughness less than about 0.89 in a step 32; providing a substrate attached to a superabrasive volume formed by the plurality of superabrasive particles in a step 34; and subjecting the substrate and the superabrasive volume to conditions of elevated temperature and pressure suitable for producing the polycrystalline superabrasive material in a step 36.

In the method 30, the substrate may be cemented tungsten carbide. The surface modified superabrasive particles may have a plurality of pits on the surface. The depth of the pits may range in size from about 5% to about 70% of the longest length of the particle. The superabrasive particles may be at least one of cubic boron nitride, diamond, and diamond composite materials.

One or more steps may be inserted in between or substituted for each of the foregoing steps 32-36 without departing from the scope of this disclosure.

EXAMPLE I

A 4-8 um monocrystalline diamond particles, e.g., diamond powder, with a nominal mean size of 6 um was coated with a nickel/phosphorous coating (90% Ni/10% P). The nickel coated diamond powder contained 30 weight percent NiP and 70 weight percent diamond. Each diamond particle was uniformly covered with the NiP coating. Two 25 gram samples of the Ni coated powder were heated in a furnace. One 25 gram sample was heated at 825° C. for 1 hour and the other at 900° C. in a hydrogen atmosphere for 2 hours. After the heating cycle was completed and the coated diamond powder was cooled to room temperature, the modified diamond particles were recovered by dissolving the nickel coated diamond in two liters of nitric acid. The mixture was then heated to 120° C. for a period of five hours. The solution was then cooled to room temperature, the liberated diamond settled and the solution was decanted. The acid cleaning and heating steps were repeated one additional time until substantially all of the nickel had been digested.

After the nickel was removed from the diamond, the converted graphite (carbon from diamond that has been converted to graphite during the reaction with nickel) was then removed from the particles using 2 liters of sulfuric acid heated to 150° C. for seven hours. The solution was then cooled to room temperature, the diamond allowed to settle and the solution was decanted. The sulfuric acid cleaning and heating steps were repeated one additional time until substantially all of the graphite had been digested.

The surface roughness and sphericity were obtained from images of the base material and modified diamond particles taken with a Hitachi model S-2600N Scanning Electron Microscope (SEM) at a 2500× magnification. The SEM images were saved as TIFF image files which were then uploaded into a Clemex image analyzer Vision PE 3.5 that was calibrated to the same magnification (2500×). In this example and for this magnification, the calibration resulted in 0.0446 μm/pixel resolution. The image analysis system measured particle size and shape parameters on a particle by particle basis. Measurements for a population of at least 50 particles from each set of experiments were generated automatically by the Clemex image analyzer. Mathematical formulas used by the image analyzer device to derive the measurements are found in the “Definitions” section above and can also be found in the Clemex Vision User's Guide PE 3.5 ©2001. Surface characteristics of the diamond particles of the five powder samples are shown in the following Table 1.

Physical and Performance Data for 4-8 um Diamond Powder Weight Powder Mean Specific Surface Material Re- Clemex, Clemex, Sample Loss, % Size, um Area m²/gram moval, mg/hr Roughness Sphericity 825C 30% Nickel (DOE #40) 35 5.6 1.29 279 0.77 0.47 900C 30% Nickel (DOE #9) 56 5.0 1.55 304 0.78 0.46 Iron-etched SJK-5 4-8 um 52 5.7 1.55 276 0.68 0.34 SJK-5 4-8 um Baseline — 5.7 0.88 126 0.89 0.64 4-8 um Polycrystalline — 4.7 2.9 168 0.84 0.60

As can be seen from FIG. 2 a, the surface texture of the modified diamond particles produced using the nickel coating method is significantly different than the surface texture of the starting material. It is apparent that, at temperatures above 800° C., the nickel reacts with the diamond and creates a unique texture that can be described by roughness and sphericity factors using the image analysis method. Based on the data obtained in this example, the roughness values changed from 0.89 to 0.77 for the 35 percent weight loss sample and from 0.89 to 0.78 for the 56 percent weight loss diamond. The sphericity values changed from 0.64 to 0.47 for the 35 percent weight loss sample and from 0.64 to 0.46 for the 56 percent weight loss diamond after the modification process.

Note that, as can be seen in Table 1, although the modification process at 900° C. resulted in a higher weight loss of diamond, and a slightly finer size and slightly higher specific surface area compared to the process performed at 825° C., there was essentially no difference in the roughness and sphericity of these two samples. The surface texture produced of the diamond particles could be qualitatively described as having many small “teeth” or cutting points. Although these features were most apparent when looking at the boundary of particle profiles, they also exist across the entire surface of each particle. It was thought that the increase in the number of cutting points, or teeth, was responsible for the improved performance of the modified diamond particles.

EXAMPLE II

A MBG-620 70/80 mesh monocrystalline diamond particles were coated with a nickel/phosphorous coating (90% Ni/10% P). The nickel coated diamond powder contained 56 weight percent NiP and 44 weight percent diamond. Each diamond particle was uniformly covered with the NiP coating. 5 grams sample of the Ni coated powder were heated in a furnace at 1000° C. for one and half hour under hydrogen environment. After the heating cycle was completed and the coated diamond powder was cooled to room temperature, the modified diamond particles were recovered by dissolving the nickel coated diamond in 500 ml of nitric acid. The mixture was then heated to 120° C. for a period of five hours. The solution was then cooled to room temperature, the liberated diamond settled and the solution was decanted. The acid cleaning and heating steps were repeated one additional time until substantially all of the nickel had been digested.

After the nickel was removed from the diamond, the converted graphite was then removed from the particles using 500 ml of sulfuric acid and 100 ml nitric acid and heated to 150° C. for seven hours. The solution was then cooled to room temperature, the diamond allowed to settle and the solution was decanted. The sulfuric acid cleaning and heating steps were repeated one additional time until substantially all of the graphite had been digested.

EXAMPLE III

Surface modified diamond was made according to Examples I or II by etching conventional diamond feed with a metal catalyst at high temperature. The presence of metal catalyst back-converted diamond to graphite and causes surface irregularities at localized spots. The resultant product was treated with acid at high temperature to remove any graphite and residual metal to give diamond micron powder with a surface topology starkly different than conventional product. The surface was rough due to large scale pitting and these sites could act as locations of fracture initiation when the diamond micron powder was subjected to HPHT conditions. Therefore, for the same applied pressure conditions, surface-modified diamond powder was crushed to a larger extent than conventional diamond micron feed.

The method of fabrication was similar to conventional PCD process. The micron feed was added to a cup of refractory metal like tantalum, niobium etc. and encased in the cup with a source of metal catalyst like cobalt, nickel etc. The cup was then surrounded by gasket material and subjected to high pressure-high temperature conditions (50 to 80 kbar, 1200 to 1800° C.) in a hydraulic press. At these HPHT conditions, the metal catalyst melted and infiltrated the pack bed of diamond. Diamond went into solution in the metal catalyst and re-precipitates out at contact points between diamond crystals eventually forming an interlinked solid structure of polycrystalline diamond as shown in FIG. 7 a. FIG. 7 b shows polycrystalline diamond by using conventional diamond feed. By using surface modified diamond, the PCD cutter showed more fractured crystals in the diamond table and a novel microstructure.

Cobalt counts for conventional diamond feed made PCD and surface modified diamond feed made PCD are 1208 and 1298 respectively. Tungsten counts for conventional diamond feed made PCD and surface modified diamond feed made PCD are 161 and 132 respectively. Compared to conventional diamond feed with surface modified diamond feed, surface modified diamond made PCD cutter has 7.4% increase of cobalt and 18% decrease of tungsten by portable XRF measurements.

While reference has been made to specific embodiments, it is apparent that other embodiments and variations can be devised by others skilled in the art without departing from their spirit and scope. The appended claims are intended to be construed to include all such embodiments and equivalent variations. 

We claim:
 1. A superabrasive blank, comprising: a plurality of polycrystalline superabrasive particles made of surface modified superabrasive particles, wherein the surface modified superabrasive particles have sphericity less than about 0.70; and a substrate attached to a superabrasive volume formed by the polycrystalline superabrasive particles.
 2. The superabrasive blank of the claim 1, wherein the superabrasive particles are at least one of cubic boron nitride, diamond, and diamond composite materials.
 3. The superabrasive blank of the claim 1, wherein the surface modified superabrasive particles have a plurality of pits on the surface.
 4. The superabrasive blank of the claim 1, wherein the surface modified superabrasive particles have a plurality of spikes on the surface.
 5. The superabrasive blank of the claim 1, wherein the depth of the pits ranges in size from about 5% to about 70% of the longest length of the particle.
 6. The superabrasive blank of the claim 1, wherein the superabrasive particles have surface roughness less than about 0.89.
 7. A method of making superabrasive material, comprising: providing surface modified superabrasive particles, wherein the surface modified superabrasive particles have surface roughness less than about 0.89; providing a substrate attached to a superabrasive volume formed by the plurality of superabrasive particles; and subjecting the substrate and the superabrasive volume to conditions of elevated temperature and pressure suitable for producing the polycrystalline superabrasive material.
 8. The method of the claim 7, wherein the substrate is cemented tungsten carbide.
 9. The method of the claim 7, wherein the surface modified superabrasive particles have a plurality of pits on the surface.
 10. The method of the claim 9, wherein depth of the pits ranges in size from about 5% to about 70% of the longest length of the particle.
 11. The method of the claim 7, wherein the surface modified superabrasive particles have a plurality of spikes on the surface.
 12. The method of the claim 7, wherein the surface modified superabrasive particles have sphericity less than about 0.70.
 13. The method of the claim 7, wherein the superabrasive particles are at least one of cubic boron nitride, diamond, and diamond composite materials.
 14. A superabrasive blank, comprising: a plurality of polycrystalline superabrasive particles made of surface modified superabrasive particles, wherein the surface modified superabrasive particles have surface roughness less than about 0.89.
 15. The superabrasive blank of the claim 14, wherein the superabrasive particles are selected from a group of cubic boron nitride, diamond, and diamond composite materials.
 16. The superabrasive blank of the claim 14, wherein the surface modified superabrasive particles have a plurality of pits on the surface.
 17. The superabrasive blank of the claim 14, wherein the surface modified superabrasive particles have a plurality of spikes on the surface.
 18. The superabrasive blank of the claim 14, wherein the depth of the pits ranges in size from about 5% to about 70% of the longest length of the particle.
 19. The superabrasive blank of the claim 14, wherein the superabrasive particles have sphericity less than about 0.70.
 20. The superabrasive blank of the claim 14, further comprises a substrate attached to a superabrasive volume formed by the polycrystalline superabrasive particles. 